/*
 *  Copyright (c) WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
 *
 *  WSO2 Inc. licenses this file to you under the Apache License,
 *  Version 2.0 (the "License"); you may not use this file except
 *  in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.wso2.balana.attr;

import org.w3c.dom.Node;
import org.wso2.balana.ParsingException;
import org.wso2.balana.PolicyMetaData;
import org.wso2.balana.XACMLConstants;

/**
 *
 */
public class AttributeSelectorFactory {

	private static volatile AttributeSelectorFactory factoryInstance;

	public AbstractAttributeSelector getAbstractSelector(Node root,
			PolicyMetaData metaData) throws ParsingException {

		if (metaData.getXACMLVersion() == XACMLConstants.XACML_VERSION_3_0) {
			return org.wso2.balana.attr.xacml3.AttributeSelector.getInstance(
					root, metaData);
		} else {
			return org.wso2.balana.attr.AttributeSelector.getInstance(root,
					metaData);
		}
	}

	/**
	 * Returns an instance of this factory. This method enforces a singleton
	 * model, meaning that this always returns the same instance, creating the
	 * factory if it hasn't been requested before.
	 * 
	 * @return the factory instance
	 */
	public static AttributeSelectorFactory getFactory() {
		if (factoryInstance == null) {
			synchronized (AttributeDesignatorFactory.class) {
				if (factoryInstance == null) {
					factoryInstance = new AttributeSelectorFactory();
				}
			}
		}

		return factoryInstance;
	}

}
